1. Field of the Invention
The present invention relates to an apparatus and a method for collecting impurities on a semiconductor wafer. More particularly, the present invention relates to an apparatus and a method for collecting metallic impurities remaining on a semiconductor wafer using a scanning solution.
2. Description of the Related Art
Generally, semiconductor devices are manufactured through a three-step process. First, a fabrication process is performed for forming electronic circuits on a semiconductor wafer. Second, an electrical die sorting (EDS) process is performed for inspecting electrical characteristics of the semiconductor devices on the semiconductor wafer. Third, a packaging process is performed for packaging the semiconductor devices in epoxy resins and individuating the semiconductor devices.
The fabrication process may include a deposition process for depositing a layer on the semiconductor wafer, a chemical mechanical polishing (CMP) process for planarizing a surface of the layer, a photolithography process for forming a photoresist pattern on the layer, an etching process for forming an electrical pattern using the photoresist pattern, an ion implantation process for implanting predetermined ions into predetermined portions of the semiconductor wafer, a cleaning process for removing impurities from the semiconductor wafer, an inspection process for inspecting the surface of the semiconductor wafer on which the layer or the pattern is formed, or other similar processes.
Impurities, such as metallic contaminants, remain on the semiconductor wafer during the fabrication process. The impurities cause deterioration in the performance of the semiconductor devices, as well as lower yields in the manufacturing of the semiconductor devices. Recently, as the degree of integration of the semiconductor devices has increased, an analysis process on the impurities has become increasingly important in the manufacturing of the semiconductor devices.
The analysis process on the impurities remaining on the semiconductor wafer includes a process for collecting the impurities and a process for analyzing a sample containing the impurities.
For example, in a conventional apparatus and method for collecting metallic impurities on a semiconductor wafer, the apparatus includes a process chamber including a loading unit for loading the semiconductor wafer and an unloading unit for unloading the semiconductor wafer, a vapor phase decomposition disposed in the process chamber for decomposing a silicon oxide layer on the semiconductor wafer, and a scanning unit disposed in the process chamber for scanning the semiconductor wafer to collect metallic impurities.
An impurity sample acquired by the impurity collection apparatus contains various types of metallic impurities, and may then be analyzed using an analysis apparatus, such as an atomic absorption spectroscope, an inductively coupled plasma (ICP) mass spectroscope, a total X-ray fluorescent analyzer, or the like.
However, the conventional impurity collection apparatus is not able to collect impurities from an edge portion of the semiconductor wafer. Accordingly, there is a need for an improved apparatus and method for collecting impurities on the semiconductor wafer.